Humidifier-or-vaporizer-for-infant-congestion, humidifier vs vaporizer guide: what’s better for baby’s nursery? when i became a new mom, i had heard about humidifiers and vaporizers, but i honestly didn’t understand the difference between the two. thinking i needed both, i registered for both (and received both).. When it comes time to equip your nursery, you might be struggling with the decision of whether to get a humidifier or a vaporizer. both of these devices work in very different ways, and it’s important to know the differences before you make a decision on either a humidifier or a vaporizer.